There are two main types of projection:

When lettering a CAD drawing, for clarity you should limit the number of fonts to:

Drawing scale refers only to the reduction of the size of a drawn object relative to the real object.

The main difference between a CAD drawing and a freehand sketch is in the appearance of lines.

The primary unit of measurement for engineering drawings and design in the mechanical industries is the:

Orthographic projections have projectors that are parallel to the plane of projection.

In orthographic projection objects can be presented at true size or scaled at a proportion of their true size.

With regard to lettering, the shapes of letters are not described as part of drawing standards.

Scale is stated as a ratio of the number of drawing units to the number of actual units.

These units are based on inch-foot and yard measurements:

Multiview projection shows one or more necessary views of an object.

Three systems are used to arrange orthographic views: first, second, and third angle projection.

The same general concepts and drafting standards apply to CAD as to drawings created by hand.

The meaning of each line on a technical drawing is indicated by its width and its particular line style.

Axonometric, oblique, and perspective sketches show objects pictorially.

Drawing units must be clearly stated on the drawing.

This is how axonometric, oblique, and perspective sketches show objects:

This type of projection is when projectors are parallel to each other, but are at an angle other than 90 degrees to the plane of projection:

Orthographic projections are a type of parallel projection.

Drawings that use U.S. customary units do not follow ANSI/ASME standards.